Background: In a previous prospective study, we found that viewing smoking in movies strongly predicted smoking initiation among adolescents 10 to 14 years of age, even after adjusting for other social influences, child and parenting characteristics. We now propose to continue following this cohort of adolescents. Aims: The primary aims of this study are to evaluate the effect of viewing smoking in movies on the risk of becoming an established smoker, evaluate the impact of age on the relationship between movie smoking exposure and smoking initiation, and identify child and parenting factors that may modify the association between exposure to movie smoking and adolescent smoking behavior Methods: To accomplish these aims, we propose a three-year longitudinal telephone survey of the 2603 adolescents who participated in our previous prospective study. These adolescents are now 15 to 19 years of age. Participants will be surveyed annually to update their smoking status, movie exposure, and other risk factors for smoking. As in our previous study, surveys will be administered using a CATI system and each individual survey will contain a unique subset of movies, randomly selected from a larger sample of top box office hits and video rentals. Survey responses will be linked with information from a content analysis of smoking in movies to estimate an individual's exposure to movie smoking. Significance: These adolescents are now at the age of highest risk for smoking uptake. The proposed follow-up is optimally timed to evaluate the influence of movies on smoking initiation in late adolescence and on established smoking. Our previous study of this cohort produced highly significant findings that catalyzed a dialogue between State Attorneys General and representatives from the motion picture industry. Results from the proposed study will extend our earlier findings by clarifying the influence of movie smoking exposure on risk of later age smoking initiation and, importantly, on progression to established smoking.